Australia was comprehensively outplayed in the semi-final - it will no doubt leave a sour taste that only an Ashes series win in September can wash out.

Whether or not Australia's 2019 World Cup can be considered a success will be a topic for debate in the coming days, and probably years.

From Justin Langer and Aaron Finch's tactics, to the squad selections made three months ago - every aspect of Australia's campaign will come under scrutiny.

These are the burning questions many will be asking.

WERE AUSTRALIA'S EGGS IN THE RIGHT BASKET?

Australia was comprehensively outplayed in the semi-final.

Given Australia's brutal dumping by its oldest rivals, the easy answer would be 'no'. But that doesn't mean it's the right one.

Had Australia won the semi-final because injuries befell England instead and their top order was the one to collapse, would the answer become 'yes'?

The fact is Australia found a set of tactics that took them from losers of six-consecutive bilateral ODI series to being one of the most-feared teams in world cricket again.

It's therefore no surprise that Australia approached the World Cup in the way it did. Besides, a semi-final finish, given where Australia was in ODI cricket at the start of 2019, is nothing short of remarkable.

Nonetheless, there is a lesson to be learned from England who showed why it's the best team in the world.

For England, preparations for the tournament were in full swing from the moment it was knocked out of the 2015 edition.

For Australia, it remained something of an afterthought until just months ago.

England rolled out its best crop of players for the majority of ODIs played in the four-year gap, while Australia's largely remained in cotton wool.

Meanwhile, the tournament hosts were forging a new game plan that would see it begin to obliterate bowling attacks with aggressive batting from ball one. And it worked - no side won more ODI cricket than England in between the 2015 and 2019 World Cups.

Australia dropped to a 34-year rankings low of sixth in the same period, and had little idea of what its best XI was.

Out of the XI that played for Australia in its first ODI of the home summer in November, only six would go on to play in Thursday night's semi-final. Australia's top six in November was stacked with big hitters such as D'Arcy Short, Chris Lynn and - to a slightly lesser extent - Travis Head, who joined fellow aggressive batsmen Glenn Maxwell, Aaron Finch and Alex Carey.

In other words, Australia was testing the waters to see if it could form its own explosive top six to match England's, which includes the likes of Jonny Bairstow, Jason Roy and Jos Buttler.

The experiment failed, so when Australia returned to the ODI arena, it did so with a more balanced side that included some quick scorers - such as Maxwell and Carey - combined with the more nuanced approaches of Usman Khawaja and Peter Handscomb.

The new formula took Australia in March to its first ODI series win in India since 2009, which was followed by another series win against Pakistan in the UAE.

Australia then understandably took the same patient tactics into the World Cup, where it became the first team to qualify for the semi-finals - doing so with a convincing win over England.

Knockout cricket is cruel though - just a seven-over lapse can see a successful squad's tactics and selections pored over with a fine-tooth comb. Australia lost 3-14 to start the semi-final despite making a habit of strong starts at the tournament.

Given Australia's world ranking (fifth), untimely injuries and the late re-introductions of Steve Smith and Warner, a semi-final appearance is nothing to scoff at.

But England's approach to the game is called 'risk-reward' for a reason. While the consequences can be dire, England has been rewarded for its brave play which Australia wasn't willing to take on, but may wish to consider for 2023.

HOW MANY MAKE IT TO THE NEXT WORLD CUP?

Australia's squad is on the mature side, and so there will be some tough decisions made in the coming years.

The only player we can say with relative certainty that won't be up for selection in 2023 is Shaun Marsh. The left-hander is comfortably the oldest player in Australia's squad, and will be almost 40 years old when the next World Cup is played.

Age is, of course, just a number and no player should be written off on their age alone. Just ask Chris Gayle (39) and MS Dhoni (38) who played at this year's tournament.

Nonetheless, history dictates that national selections become far less likely after turning 35 - for those who haven't retired already anyway. The mark is probably closer to 33 for fast bowlers.

From Australia's batting crop, Marsh, Finch, Warner and Khawaja will all be 36 and older at the 2023 World Cup, while Glenn Maxwell will be 34.

Smith will be approaching his 34th birthday, while Handscomb should have plenty of cricket left in him at 31.

As for the bowlers; Pat Cummins and Adam Zampa should still be in, or close to, their prime at 29 and 31 respectively, as should fast-bowling all-rounder Mitch Marsh at 31.

Mitchell Starc, however, will be closer to the end of his career at 33, as will all-rounder Marcus Stoinis (33), Nathan Coulter-Nile (35) and Nathan Lyon (35). Jason Behrendorff and Kane Richardson will be 32.

Should his form continue, Alex Carey would be in prime position to wear the gloves again for Australia at the World Cup at 31.

WAS THE BIG SHOW A NO SHOW?

Not entirely, but it was certainly a tournament below his standards.

Maxwell made just 177 runs at 22.12 in a personal campaign that fell flat on its face - he didn't score more than 25 in his last four innings.

But while Maxwell didn't score big at the tournament - his highest score was an unbeaten 46 - the importance of some of his earlier scores has been understated. For a brief moment, he was brilliant.

His 46 off 25 balls against Sri Lanka took Australia to an imposing total that helped claim an important win, given the difficulty of the team's closing fixtures.

That innings seemed to play him into some form, as he was at his devastating best the following game against Bangladesh. He staggeringly crushed 32 runs off just 10 balls to, once again, put Australia on the path towards a big total and a win. He could only be stopped in the end by his teammate, Khawaja, who ran him out in comical fashion.

And that's when it all went horribly downhill. His remaining scores were just 12, 1, 12 and 22.

In other words, Maxwell wasn't a no show at the World Cup, rather he was more a disappearing act.

He also lost his wicket to a short ball four times during the tournament, which has worryingly uncovered a weakness sides will target in the future.

WERE SELECTORS RIGHT TO SNUB JOSH HAZLEWOOD?

Jason Behrendorff should hold his head up high - but Australia missed Josh Hazlewood.

The World Cup doesn't exist in a vacuum and Australia has a little thing called the Ashes on the horizon, so there were other factors at play in Hazlewood's non-selection.

But Australia definitely would have been better off with another bowler of his calibre.

That's not to say Hazlewood would have changed the result of the semi-final. Australia wasn't even in the same area code as England.

Nonetheless, his ability when the ball isn't swinging - which it usually didn't - would have come in handy.

Behrendorff should still hold his head up high - he was, at times, brilliant. Few will soon forget his 5-44 against England at Lord's in the group stage.

It's true, however, that he only made a genuine mark on matches when there was swing and seam on offer for the fast bowlers. He was given an extra leg-up by being handed the new ball too.

There was very little swing or seam on offer at Edgbaston on Thursday and Australia's bowlers were taken to task.

It was brutal enough to watch for most Australians, so imagine how it must have felt for Hazlewood.

WHERE SHOULD ALEX CAREY BAT MOVING FORWARD?

Alex Carey was revelation for Australia at the World Cup.

Up the order - there's very little doubt about it. It's just a matter of how far up.

Carey was one of Australia's best performers with the bat at the tournament, scoring 375 runs at 62.50.

He made the vast majority batting at No.7, despite the ongoing struggles of Maxwell and Stoinis who were immediately above him in the order.

The left-hander was a revelation, and he continued to improve the longer it went on.

Carey closed out the group stage with consecutive half-centuries, before playing a gutsy innings in the semi-final.

Australia was in crisis at 3-14 in seventh over when he was told to walk out at No.5 and breathe life into the innings.

And he did - no matter how daunting the task was on the grand stage, nor how hard he was rocked by a Jofra Archer bouncer that left him with a deep gash on his jaw.

Having scored at more than a run-a-ball (113.44) all tournament, Carey bunkered down with Smith and delivered the patient innings his side so desperately needed.

He was, however, guilty of not going on with the job - out for 46 off 70 balls. But his 103-run partnership with Smith briefly gave Australia a fighting chance.

It was a performance that was made possible by a well-overdue promotion, former Australia opener Michael Slater said.

"He's deserved this opportunity at No.5. He's worked so hard," Slater said during Carey's innings.

"He's come in too late, too often and when he's come in late he's had such an impact that, little by little, the powers that be could see that he needs more overs of batting.

"He's perfect for it. He's got a good, simple, solid technique."

No.5 could be the perfect fit for Carey, although there is still some merit in grooming him for a return to the opening slots in the future.

Warner and Finch will both be 36 by the time the next World Cup rolls around, and so Australia may be looking for two new ODI openers before then.

Carey opens the batting for the Adelaide Strikers in the BBL, making 772 runs there at 36.76 over the past two seasons.

He has had three chances as an ODI opener, making just 47 runs at 15.66. But given the small sample size and the fact he has plenty of opening experience in white-ball cricket, it's not hard to envisage a scenario in which he comes good there for Australia.

WHERE TO NOW FOR ADAM ZAMPA?

Time is on Zampa's side. He's still only 27.

But going to the World Cup this year must feel like a bittersweet experience for the out-of-favour leg-spinner. It remains to be seen whether he can ever - beyond a shadow of a doubt - be Australia's go-to spin bowler.

He has been before - mainly in 2016 when he was the world's leading ODI wicket-taker with 30 at 27.80. Even so, he spent the following two years in and out of the side.

But as hype built around a World Cup that was supposedly going to see wicket-taking leg-spinners dominate, Zampa seemingly gained selectors' trust once more.

He played in all ten of Australia's ODIs in March, taking 18 wickets at 30.27 against India and Pakistan in Asia. So it came as no surprise when it was Zampa picked as Australia's sole-spinner - not Lyon - when Australia's World Cup campaign started against Afghanistan.

Zampa took 3-60 in that match, but figures of 1-108 with an economy rate of 6.75 across his next two matches saw him dropped, as Australia scrapped picking a specialist spinner altogether.

When selectors later looked to retain a spin bowler, Zampa was given just one more shot against Bangladesh (1-68 off nine overs) before Lyon was handed a jersey instead.

Zampa didn't bowl another ball for the tournament, as Lyon ended the World Cup with three wickets at a far more economical 5.32 compared to the leg-spinner's 7.15.

Playing at a 50-over World Cup for the first time was no doubt a career highlight for Zampa.

But it was a tournament in which he was meant to be a key cog for Australia, and he ended up being a surplus to requirements instead.